1. Progress in the Application
of Hadron Therapy
(protons or ions)
Marco Schippers

2. The boost in particle therapy
more
hospital
based
mostly in labs
Loma Linda
(Ca, USA)
Particle therapy group: until 2015 > patients treated

3. Contents
Introduction: particle therapy
Accelerators
Synchrotron
Cyclotron
Treatment facilities
What is so special?

4. X-ray dose heart X-ray beams (IMRT ) from 7 directions X-rays lung
Spinal cord

5. Dose profile of protons2 4 6 8 10 12 14 16 18
Bragg
peak
Dose (a.u.)
Depth in tissue (cm)

6. X-rays vs. Protons heart heart Proton beams X-ray beams (IMRT )
from 7 directions
Proton beams
from 3 directions
X-rays
Protons
lung
heart
Spinal cord
heart
lung
Spinal cord
pictures: Medaustron

7. Biological effect of Carbon ions
RBE>1:
Less dose for
same cell killing
RBE= 1.1
RBE≈ 3
electron track (or energy) density at nm scale effects RBE ( this means: RBE≠ 1 )

8. Pencil beam scanning kHz-Intensity modulation intensity 0 time (ms) 10
Spot scanning: step&shoot
Continuous scanning
time (ms)
intensity
kHz-Intensity modulation
allows fast target repainting:
15-30 scans / 2 min.

9. Present accelerator choice
3.5 m
e.g:
Boston
Florida
Seoul
Wanjie
PSI
München
Orsay
e.g.:
Loma Linda
Houston
Tsukuba
cyclotron synchrotron
Protons in use, 3.5-5 m
in use, 8-10 m
Carbon ions in design, 6 m
in use, 25 m

10. Proton source + injector
Synchrotron
Hitachi Ltd
Extracted beam
Protons only:
( ~8 m)
synchrotron
Proton source + injector
synchrotron
Ions (p-C):
( ~25 m)
Heidelberg
Extracted beam
Injector
Ion sources

11. Synchrotron beam structure in time
Beam intensity
Time 
1-10 sec
0.5-1 sec
in development
“spill” time
fill ring with ~1011 particles
accelerate to desired energy
extract slowly during 1-10 sec
decelerate and dump unused particles

12. Cyclotron 230 MeV (IBA, SHI,1996) 250 MeV (ACCEL/Varian,2005)
SC coils: diam 3.5 m, 100 tons
230 MeV (IBA, SHI,1996)
iam. 5 m, 200 tons

13. E-adjustment with cyclotron
250 MeV cyclotron
All following magnets:
1% field change
in ms
At PSI:
Graphite degrader
MeV

14. Small cyclotron Synchro-Cyclotron fRF 1 ms very strong magnetic field:
B decreases with radius
 Tcircle increases with radius.
SO: decrease fRF with radius and extract
Repeat 1000 x per sec
time
fRF
1 ms
Each pulse: set intensity at source within ms
(=> typ 10-30% accuracy)
=> Spot scanning requires >2 pulses per spot.

15. Synchro-Cyclotron 8-10 T 250 MeV Synchro-cyclotron on a gantry
First system installed in 2013

16. Accelerator status (protons)
cyclotron
synchrotron
small
synchro-
cyclotron
linac
Current Useability
=> Quality
FFAG
laser
Dielectr. wall
linac
Plasma
wake field
Now Mañana
Time until useable

17. Proton therapy: multi-room facility
Cyclotron
or synchrotron
gantries
At cyclotron:
degrader+
energy selection
beam transport
IBA

18. Gantries
10-12 m
IBA
~90 t
Loma Linda (Optivus)

19. PSI Gantry-2: fast 3D scanning
Eros Pedroni
David Meer

20. Gantry for carbon-therapy
HIT, Heidelberg

21. NEW: SC gantries NIRS, Japan SC dipoles Scanning XY Pronova,
Knoxville, USA

22. PSI’s superconducting gantry design
Collimators
Degrader
Scanning
magnets
Rotation axis Isocenter
combined function, achromatic bending
Degrader mounted on the gantry
Momentum acceptance of approx. ±12.5 %
Treatment of the small tumors without change of the SC magnet field

23. Acc.Lab  Hospital What is so special? Radiologist operates
Operators
Technicians
Experienced workshops
More improvised actions
Radiologist operates
CE/FDA-certification: PROCEDURES
Local technicians:only small repairs
Service by equipment company

24. Safety  Availability Patient safety: Machine interlocks:
Separate interlock systems e.g. :
Machine interlocks:
all components technically OK
More specially for treatments
Area access & area dose:
Doors closed, dose rate < µSv/h
Patient safety:
Dose delivery as planned

25. Patient safety interlock system
Redundancy
measurement
BEAM off
Alarm
level
stop
Redundancy
Redundancy
Patient safety interlock system
stop
Alarm
level

26. Operation: non-accelerator experts
What has happened ?
Strong need for
ERGONOMIC display of:
Status
Instructions
NO BEAM

27. Control and safety: What is so special?
Accelerators for Medical Application
What is so special?
Technics: dedicated, but not on the limit of technology ….but…
Reliable, Reproducible, Reliable, Reproducible
Operation: by non-accelerator experts
strictly according procedures
Control and safety:
VERY DEDICATED and SPECIAL :
Reliable & Redundant, but not too sensitive

28. SUMMARY Dose: finite range maximum dose at end of track
Apply the dose by Pencil Beam Scanning
Accelerators for Medical Application:
Cyclotron
Synchrotron
Medical applications: VERY Special Operation
Facilities: Gantry aims the beam from all directions
Recent development: SC magnets

29. Thank you !! …. Motivation …. first scanning gantry : PSI, 1996
Gantry: Eros Pedroni
Tumours in kids: Beate Timmermann, Gudrun Goitein